Wow interesting, you buy for what do you need to use it for and not the other way around.
You can start buying groceries from Fresh also, which is what I do like heavy ones like 4kg+2kg surf excel costs 1200, 2 or so which will again run for few quarters.
Best is if you buy lot of things from Amazon then only it makes sense to buy Amazon shopping voucher. I am planning to accumulate when I anticipate heavy need like a premium phone or a iPad which is on my list for few years now
Or better to buy Amazon pa ly voucher which I use to pay all utility bills like mobile, internet or EB, Gas etc...which are expected every month